Barack Obama is afraid he might be a warmonger at heart. Who knew? But making war against an Islamic enemy? That defies everyone's imagination.

The president keeps changing his arguments for his deal with the mullahs in Iran, and the tone of his denunciations of anybody who argues with him grows ever harsher and disrespectful. The latest refinement of tone is his assertion that it's his way or the highway, and that war with Iran lies at the end of that forbidden highway.

But who would start such a war? He doesn't say. As crazy as the mullahs are, the craziness lies in a distorted theology, not in statecraft. The mullahs are smart enough not to believe everything they say, and make war against the United States. They don't expect 62 virgins in paradise, and are eager to stay alive here. We can logically conclude that Mr. Obama is afraid that he might be the one to start the war. Who else does he think it could be? His "it's me or war" is rendered nonsense, and he knows it.

Many bad things happen when a leader is weak, confused and forever searching for a reason to do nothing. For all his softness on Islam, he has little insight into the men who send out mobs to cry "death to America." He can't imagine that men who listen to the call to the evening Muslim prayer that so captivated him as a boy growing up in Indonesia  "the prettiest sound on Earth"  actually dream of bringing death to America.

The international order so carefully put together, and guarded so faithfully, by American presidents after the Cold War was won, has begun to unravel under this president to the consternation of America's most faithful allies and to the unexpected delight of the nation's enemies. The anarchy that follows this unraveling is the legacy that he will leave behind him when he takes that long, lingering helicopter ride out of town on inauguration day 2017.

"When [Mr.] Obama came to office in 2009," writes Alexander Woolfson in Standpoint, a London political monthly, "it would have been unimaginable that a caliphate could be allowed to thrive in the midst of the Middle East, or that a U.S. president would be foolish enough to exploit ancient Persian and Arab enmity for the purposes of American retrenchment. [Mr.] Obama's now familiar refrain is to counsel "strategic patience" while suggesting that America cannot solve every world problem. He remains oblivious to the fact that his worldview is the problem. ISIS has created a version of the future which Obama appears unable to grasp. Its caliphate is being sustained through the mass murder and repression of those who do not belong."

"Unable to grasp." That will be the epitaph and the legacy of Mr. Obama's presidency. When an American president says he wants to "lead from behind," the enemies in the Middle East, and there are many, naturally assume that he means he wants to fool about on the margins, make speeches, play a little golf (or a lot), insult those who disagree with him. Commanders in chief no less than privates and corporals can decamp from sworn duty.

President Obama flinches from the sound of the guns. He orders air strikes, everyone's favorite weapon of war, reluctantly and with half a heart. In the month before ISIS captured Ramadi, the United States flew 165 air strikes. Bill Clinton ordered that many in a single day in the campaign in Kosovo. George H.W. Bush ordered 42,000 in a month of Operation Desert Storm. Only Mr. Obama can be surprised when the situation on the ground not so slowly deteriorates, Iraqi soldiers flee their posts and the black flags of ISIS steadily advance, fluttering in the bluster of White House spin.

He can't talk about a strategy in the Middle East because he doesn't have one. He thinks he doesn't need one because ISIS will implode. He cannot even bring himself to say the words "Islamic violence," and thus cannot deal with the nature of radical Islam. He insists that ISIS is just another manifestation of terrorism, not a caliphate that demands to be recognized as a state. "Nobody," he says, "is under illusions that [ISIS] can actually in a sustained way feed people or educate people or organize a society that would work."

Blinded by what he wants to see, he would be a bowl of mush in the hands of the mullahs if push comes to shove with the United States. Barack Obama, paralyzed by the ideology he learned on the left, could never pull the trigger in a confrontation with Iran, and the mullahs  and the world  know it.

The summer soldiers in the U.S. Senate need not fear war if they take the highway rather than the Obama way. They should fear the Islamic bomb if they don't.